A5067807489- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Magnetic Bearings and Levitation Dynamics
- Adaptive optics and wavefront sensing
- Space Science and Extraterrestrial Life
- Astronomical and nuclear sciences
- Nuclear physics research studies
- Inertial Sensor and Navigation
- Space Exploration and Technology
- Business Process Modeling and Analysis
- Theoretical and Computational Physics
- Mechanics and Biomechanics Studies
- Astrophysics and Cosmic Phenomena
- Marine and environmental studies
- Geophysics and Gravity Measurements
- Physics of Superconductivity and Magnetism
- Complex Systems and Time Series Analysis
Universidad de La Laguna
2023-2024
Instituto de Astrofísica de Canarias
2023-2024
Institute of Astronomy
2016-2023
European Southern Observatory
2020-2023
KU Leuven
2016-2023
Université Libre de Bruxelles
2016-2023
The original Kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), continue to be an astrophysical goldmine. Because of this, thorough investigations the ~ 200,000 stars observed by remain paramount importance. In this paper, we present a state-of-the-art characterization targets based on Gaia DR3 data. We place color-magnitude diagram (CMD), account for effects interstellar extinction,...
Spectro-seismic measurements of red giants enabled the recent discovery stars in thick disk that are more massive than 1.4 M_sun. While it has been claimed most these younger rest typical stars, we show evidence they might be products mass transfer binary evolution, notably evolved blue stragglers. We took new radial velocities a sample 26 from APOKASC, including 13 "young" and "old" with similar stellar parameters but masses below 1.2 M_sun found appear to systems respect stars....
This paper provides long-period and revised orbits for barium S stars adding to previously published ones. The sample of with strong anomalies comprise all such present in the Lu et al. catalogue. We find orbital motion extrinsic monitored. obtain longest period known so far a spectroscopic binary involving an star, namely 57 Peg order 100 - 500 yr. mass distribution stars, which ranges from 1 3 Msun, tail extending up 5 Msun case mild stars. high-mass comprises mostly high-metallicity...
Barium (Ba) dwarfs and CH subgiants are the less-evolved analogues of Ba giants. They F- to G-type main-sequence stars polluted with heavy elements by a binary companion when latter was on Asymptotic Giant Branch (AGB). This is now white dwarf that in most cases cannot be directly detected. We present large systematic study 60 objects classified as or subgiants. Combining radial-velocity measurements from HERMES SALT high-resolution spectra data CORAVEL CORALIE, we determine orbital...
Context. Masses are one of the most difficult stellar properties to measure. In case white-dwarf (WD) companions Barium (Ba) stars, situation is worse. These stars dim, cool, and observe via direct methods. However, Ba were polluted by asymptotic giant branch (AGB) progenitors these WDs with matter rich in heavy elements, their WD contain key information about binary interaction processes involving AGB slow neutron capture process ( s -process) nucleosynthesis. Aims. With this study, we aim...
This study is a contribution in comprehending the role of binarity upon late stages stellar evolution. We determine binary status six Galactic RV Tauri stars, namely DY Ori, EP Lyr, HP IRAS 17038-4815, 09144-4933 and TW Cam, which are surrounded by dusty disc. also place them on HR diagram, thereby establishing their evolutionary nature. All stars included this binaries with orbital periods ranging between $\sim$ 650 1700 days eccentricities 0.2 0.6. The mass functions range 0.08 to 0.55...
Context. Among carbon-enhanced metal-poor (CEMP) stars, some are found to be enriched in slow-neutron capture ( s -process) elements (and then tagged CEMP-s), have overabundances rapid-neutron r (tagged CEMP-r), and characterized by both - -process enrichments CEMP-rs). The current distinction between CEMP-s CEMP-rs is based on their [Ba/Fe] [Eu/Fe] ratios, since barium europium predominantly produced the -process, respectively. origin of abundance differences stars presently unknown. It has...
(Abridged) The Maunakea Spectroscopic Explorer (MSE) is an end-to-end science platform for the design, execution and scientific exploitation of spectroscopic surveys. It will unveil composition dynamics faint Universe impact nearly every field astrophysics across all spatial scales, from individual stars to largest scale structures in Universe. Major pillars program MSE include (i) ultimate Gaia follow-up facility understanding chemistry distant Milky Way, including outer disk stellar halo...
Barium stars are s-process enriched giants. They owe their chemical peculiarities to a past mass transfer phase. During which they were polluted by binary companion, at the time was an AGB star, but is now extinct white dwarf. thus ideal targets for understanding and constraining in low intermediate-mass stars. We derive abundances of large number heavy elements order shed light on conditions operation neutron source responsible production s-elements former companions barium Adopting...
Binary post-asymptotic giant branch (post-AGB) stars are thought to be the products of a strong but poorly-understood interaction during AGB phase. The aim this contribution is update orbital elements sample galactic post-AGB binaries observed in long-term radial-velocity monitoring campaign. Radial velocities computed from high signal-to-noise spectra by use cross-correlation method. curves fitted using both least-squares algorithm and Nelder-Mead simplex algorithm. We Monte Carlo method...
ABSTRACT We provide three statistical model prescriptions for the bolometric corrections appropriate B-type stars as a function of (i) Teff, (ii) Teff and log g, (iii)Teff, g [M/H]. These models have been calculated 27 different filters, including those Gaia space mission, were derived based on two grids assuming LTE LTE+NLTE, respectively. Previous such work has mainly limited to single photometric passband without taking into account non-local thermodynamic equilibrium (NLTE) effects...
The latest Gaia Focused Product Release (FPR) provided variability information for $\sim$1000 long-period red giant binaries, the largest sample to date of this binary type having both photometric and spectroscopic time series observations. We cross-matched DR3 measurements with catalogue candidates from FPR, radial velocity information. Combined photo-geometric distances, extinction, bolometric magnitude, luminosity, radius mass were estimated. ELL variables are characterized be low...
The latest Gaia Focused Product Release (FPR) has provided variability information for ∼1000 long-period red giant binaries, including almost ∼700 ellipsoidal binary candidates, thus providing the largest sample to date of this type with both photometric and spectroscopic time series observations. We aim characterize physically (luminosity, mass, radius) chemo-dynamically (metallicity α/Fe Galactic velocities) population candidates a subsample rotational variable from FPR by combining...
The original kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), continue to be an astrophysical goldmine. Because of this, thorough investigations the ∼ 200,000 stars observed by remain paramount importance. In this paper, we present a state-of-the-art characterization targets based on gaia DR3 data. We placed color-magnitude diagram (CMD), accounted for effects interstellar...
Context. Asteroseismic modelling of the internal structure main-sequence stars born with a convective core has so far been based on homogeneous analyses space photometric Kepler light curves four years in duration, to which most often incomplete inhomogeneously-deduced spectroscopic information was added break degeneracies. Aims. Our goal is twofold: (1) compose an optimal sample gravity-mode pulsators observed by telescope for joint asteroseismic and stellar modelling, (2) provide...
With the availability of parallaxes provided by Tycho-Gaia Astrometric Solution, it is possible to construct Hertzsprung-Russell diagram (HRD) barium and related stars with unprecedented accuracy. A direct result from derived HRD that subgiant CH occupy same region as dwarfs, contrary what their designations imply. By comparing position in STAREVOL evolutionary tracks, evaluate masses, metallicity known. We used an average [Fe/H] = −0.25 mass distribution giants. The peaks around 2.5 M⊙ a...
Context. Hundreds of candidate hybrid pulsators intermediate type A–F were revealed by recent space missions. Hybrid allow us to study the full stellar interiors, where both low-order p - and high-order g -modes are simultaneously excited. The true stars must be identified since other processes, related multiplicity or rotation, might explain presence (some) low frequencies observed in their periodograms. Aims. We measured radial velocities 50 δ Scuti − γ Doradus from Kepler mission with...
56 UMa is a wide binary system that contains chemically peculiar red giant and faint companion. Due to its surface chemical abundances, the was classified as barium (Ba) star. This implies companion has be white dwarf, since Ba stars form when mass transferred them from an s-process rich Asymptotic Giant Branch (AGB) However, in case of UMa, might too massive progeny AGB star efficiently produced elements such barium. In this Letter, we revisit orbital parameters perform full spectral...
Among the known groups of pulsating stars, $\delta$ Sct stars are one least understood. Theoretical models do not predict oscillation frequencies that observations reveal. Complete asteroseismic studies necessary to improve these and better understand internal structure targets. We study star HD 41641 with ultimate goal understanding its pattern. The target was simultaneously observed by CoRoT space telescope HARPS high-resolution spectrograph. photometric data set analyzed software package...